| MPS | Syndrome(s) | GAGs accumulated | Enzyme deficiency | Genetic mutation | Mode of inheritance | Main clinical presentation | |
| I | Hurler’s Scheie Hurler-Scheie | Dermatan, heparan sulphate | α-L-iduronidase deficiency | IDUA 4p16,3 | Autosomal recessive | Progressive mental decline and loss of physical skills by 2-4 years of age. Hearing loss, enlarged tongue and corneal clouding Restricted joint movement Hurler’s syndrome is the most severe form of MPS I. Scheie is the mildest form of MPS I. Children with Scheie syndrome have normal intelligence or may have mild learning disabilities Hurler-Scheie is less severe than Hurler syndrome alone | |
| II | Hunter’s | Dermatan, heparan sulphate | Iduronate sulfatase deficiency | IDS Xq28 | X-linked recessive | Two clinical subtypes which are neuropathic (with CNS involvement) and non-neuropathic (without CNS involvement) No corneal clouding Hepatosplenomegaly Hydrocephalus Heart valve abnormalities | |
| III | Sanfilippo (Subtypes A-D A = Most severe) | Heparan sulphate | A: heparan N-sulfatase B: alpha-N- acetylglucosaminidase C: acetyl-CoAlpha- glucosaminide acetyltransferase D: N-acetylglucosamine 6-sulfatase | A: SGSH 17q25,3 B: NAGLU 17q21.2 C: HGSNAT 8p11.21-p11.1 D: GNS 12q14,3 | Autosomal recessive | Progressive dementia, aggressive behaviour, hyperactivity, seizures, some deafness and loss of vision, and an inability to sleep more than a few hours at a time Delayed mental, motor and language skill development | |
| IV | Morquio (Subtypes A and B) | Keratan and chondroitin sulphate, | A: N-acetylgalactosamine- 6-sulfatase B: beta-galactosidase | A: GALNS 16q24,3 B: GLB1 3p22,3 | Autosomal recessive | Onset is between ages 1- and 3-years Neurological complications include spinal nerve and nerve root compression; progressive skeletal changes, particularly in the ribs and chest; conductive and/or neurosensory hearing loss and clouded corneas. Intelligence is normal unless hydrocephalus develops and is not treated | |
| VI | Maroteaux Lamy | Dermatan, chondroitin sulphate | N-acetylgalactosamine 4-sulfatase | ARSB 5q13-14 | Autosomal recessive | Skeletal abnormalities; macrocephaly; coarse facial features; macroglossia; contractures; Carpal tunnel syndrome; spinal stenosis; hepatosplenomegaly; umbilical hernia, clouded corneas; growth stops at age 8 years | |
| VII | Sly | Dermatan/ heparan/chondroitin sulphate | beta-glucuronidase | GUSB 7q11,21 | Autosomal recessive | Hydrops fetalis (severe form); mild to moderate intellectual disability; communicating hydrocephalus, nerve entrapment, corneal clouding; short stature; joint stiffness and restricted movement, and umbilical and/or inguinal hernias. | |
| IX | Natowicz | Hyaluronan | Hyaluronidase deficiency | HYAL1 3p21,3 | Autosomal recessive | Periodically painful soft tissue masses around the joints, acquired short stature and erosion of the hip joint, although joint movement and intelligence are normal | |